System for diagnosing an input-output control unit

ABSTRACT

A system according to the present invention diagnoses an inputoutput control unit in the computer control system comprising a computer, the input-output control unit and a process. The diagnoses is carried out without separating the connections between the input-output control unit and the process and without using a simulator. Firstly, the diagnose mode signal is applied to the input-output control unit and separates this input-output control unit from the process. Secondly, the computer applies the diagnose signal to the input-output control unit and reads the output of the input-output control unit; thus the computer diagnoses the input-output control unit.

451 Jan. 9, 1973 [54] SYSTEM FOR DIAGNOSING AN INPUT- OUTPUT CONTROLUNIT [75] inventors: Norito Yolhitake, Kawasaki; Ryojl llnazelri,Yokohama, both of Japan [73] Assignee: Fujitsu Limited,

Japan [22] Filed: June 18, 1971 [21] Appl. No.: 154,497

Kawasaki-shi,

[30] Foreign Application Priority Date June 22, 1970 Japan ..45/54250[52] U.S. Ci. ..340/172.5 [5 1] Int. Cl ..G06i 1 1/00 [58] Field ofSearch ..340/l 72.5

[56] References Cited UNITED STATES PATENTS 3,510,843 5/1970 Bennett eta1. ..340/172.5

Ottaway et al. ..340Il72.$ Kwnn et al ..340/l72.5

Primary Examiner-Gareth D. Shaw Attorney -Wialeson, Kimmelman & Ratner[57] ABSTRACT A system according to the present invention diagnoses aninput-output control unit in the computer control system comprising acomputer, the input-output control unit and a process. The diagnoses iscarried out without separating the connections between the inputoutputcontrol unit and the process and without using a simulator. Firstly, thediagnose mode signal is applied to the input-output control unit andseparates this input-output control unit from the process. Secondly, thecomputer applies the diagnose signal to the input-output control unitand reads the output of the input-output control unit; thus the computerdiagnoses the input-output control unit.

6 Claims, 4 Drawing Figures 1/0 CONTROL UNIT COMPUTER J PROCESS (R Is 3PAIENIEDJIIII 9|975 3.710.350

SHEET 1 OF 2 PRIOR ART 0s COMPUTER 1/0 CONTROL i PROCESS UNIT IS -I 2 .9

SIMULATOR PRIOR ART 2 f 0s COMPUTER CONTROL PROCESS UNIT * LEVELCONVERT] Fig. 3

D5 1/0 CONTROL UNIT COMPUTER OM PROCESS 1 CT DB LI (R \IG L3 PATENTEDJAH9 I975 SHEET 2 UF 2 DS I/O CONTROL UNIT COMPUTER A SYSTEM FOR DIAGNOSINGAN INPUT-OUTPUT CONTROL UNIT The present invention relates to a systemfor diagnosing an input-output control unit which is used to feedinformation into a computer or to extract information from a computer.

In recent years, the field of the application of the electronic computerhas been increasingly enlarged, and it is now found in all fields, e.g.data collection, process control, business systems, etc. The electroniccomputer can perform every kind of function such as an operationfunction, a decision function, and a memory function. So, by thepredetermined program and via the input-output control unit, theelectronic computer carries out the necessary information processing ofthe received signals from the process, and sends the control signal tothe above-mentioned process.

The input-output control unit receives every kind of process signalssuch as digital inputs, pulse inputs, interruption inputs, analogueinputs and send control signals in the form of digital outputs, pulseoutputs, analogue outputs to the process. The input-output control unitis composed of every kind of register, counter, switching circuit,commutating circuit, analogue-todigital converter, digital to analogueconverter, etc., and stores or reads the information of the addressdesignated by the electronic computer. When the object of the process islarge scale the above-mentioned input-output control unit will includemany kinds of input and output circuits.

We now define the technical terms used in the description of the presentinvention.

The input-output control unit" this unit controls the input informationfrom the input devices of the computer, such as a data collectionterminal, a machine to be controlled, a control device such as achemical plant, a paper tape reader, etc., and the output information tothe output devices of the computer, such as, a printer and a displayunit, and this device is, in some cases, provided separately from theelectronic computer, and in some cases, included in the electroniccomputer.

"Process" this is a generic term applied to the above-mentioned inputand output devices, such as the data collection terminal, the machine tobe controlled etc., connected to the input-output control unit.

Conventional methods for diagnosing an input-output control unit in thecase of an introduction test, a management problem, a periodicalexamination, etc., are carried out as described below. The firstconventional method is carried out by separating the connec tionsbetween the input-output control unit and the process, and connecting asimulator to said input-output control unit. The second conventionalmethod is also carried out by separating the connections between theinput-output control unit and the process, and connecting a levelconverter to said input-output control unit, converting a level ofpredetermined signal pattern of the computer to a constant level, andsending it back to said computer. However, in the above-mentioned twomethods, the connections between the input-output control unit and theprocess must be separated at every occasion of the diagnosis and furthera simulator or a level converter is always required. These are the maindrawbacks of the conventional methods.

The object of the present invention is to overcome the above-mentioneddrawbacks.

Another object of the present invention is to diagnose the input-outputcontrol unit by a diagnose mode of the computer, without separating theconnections between the input-output control unit and the process.

A further object of the present invention is to diagnose theinput-output controlling device without using a simulator, a levelconverter, etc.

A still further object of the present invention is to convert both theinput and output circuits of the inputoutput control unit into thediagnose mode simultaneously and at the same time diagnose theinput-output control unit.

Further features and advantages of the present invention will beapparent from the ensuing description with reference to the accompanyingdrawings to which, however, the scope of the invention is in no waylimited.

FIG. 1 is a block diagram explaining a conventional method fordiagnosing the input-output control unit,

FIG. 2 is a block diagram explaining another conventional method fordiagnosing the input-output control unit,

FIG. 3 is a block diagram explaining the system for diagnosing theinput-output control unit according to the present invention,

FIG. 4 is a block diagram explaining another system for diagnosing theinput-output control according to the present invention.

Referring FIG. I, in the conventional system, the points a and b of thejunction points between the inputoutput control unit 2 and the process 3are separated, and the simulator 4 is connected to the input-outputcontrol unit 2. The simulator 4 generates the signal for diagnosing theinput-output control unit 2. A computer 1 feeds a predetermined signalpattern to the simulator 4 via the input-output control unit 2, and inaccordance with the above-mentioned signal pattern, the simulator 4generates a predetermined signal pattern and feeds it to the computer 1via the input-output control unit 2. The computer 1 receives thepredetermined signal pattern generated on the simulator 4 and therebythe computer 1 diagnoses the input-output control unit 2.

Referring in FIG. 2, in another conventional system, the points a and bof the junction points between the input-output control unit 2 and theprocess 3 are also separated similarly as in FIG. I, and in this case, alevel converter 5 is connected to the inputoutput control unit 2. Thelevel converter converts the level of the predetermined signal patternfrom the computer 1 to the predetermined constant level and sends itback to the computer 1 via the input-output control device 2. Thecomputer 1 receives the signal pattern which is converted to theconstant level by the level converter 5, and thereby the computer Idiagnoses the input-output control unit 2. In the above-mentioned twomethods, the connections between the input-output control unit and theprocess must be separated at every occasion of the diagnosis and furthera simulator or a level converter is always required.

Referring to FIG. 3, the system for diagnosing the input-output controlunit 6 according to the present invention is shown in the case where thepulse counter CT is diagnosed. In this case, the input-output controlunit 6 is further provided with an inhibit gate IG and an OR gate R. Aninformation signal from the process 3 and the diagnose mode signal DMfrom the computer 1 are applied to the inhibit gate 10, and the outputof the inhibit gate and the diagnose signal DS from the computer 1 areapplied to the pulse counter CT to be diagnosed. The date bus DB isconnected between the pulse counter CT and the computer 1, and thecomputer 1 reads the contents of the pulse counter CT by the readinstruction.

In the case of normal operation, the diagnose mode signal DM is notapplied to the input-output control unit 6, and the information signalfrom the process is applied via the inhibit gate 16 and the OR gate R tothe counter CT. in the case of diagnosing the input-output control unit6, the diagnose mode signal DM is applied from the computer 1 or a testpanel (not shown in the figure) to the inhibit gate IO. Therefore, theinput-output control unit 6 is completely out off from the process 3 bythe inhibit gate lG. Next, the diagnose signal DS is feed from thecomputer 1 via the OR gate to the circuit to be diagnosed, in this casefor example, the pulse counter CT. In this case, the diagnose signal DSis of suitable type for diagnosing the pulse counter CT, such as forexample, a predetermined number of pulses. The computer 1 reads saidnumber of pulses and via the data bus DB the contents of the pulsecounter CT which is sent to the computer 1. When the contents of thepulse counter CT coincides with said number of pulses, the pulse counteris diagnosed as being in the state of normal operation.

The above-mentioned system is applied to the case where a number ofpulse counters CT CT CT, are included in the input-output device 6.Referring to FIG. 4, in the case of diagnosing the input-output device7, the diagnose mode signal DM is applied simultaneously to the inhibitcircuits lG, 10,, connected respectively via the OR gates R, R, to thepulse counter CT, CT, to be diagnosed, and thereby the input-outputdevice is completely out off from the process 3. The diagnose signal isalso applied simultaneously to the OR gates R, R,, connectedrespectively to the pulse counter CT, CT,,. Further, the addressinformation is applied via an address bus AB to the decorder D, D,,, andoutputs of the pulse counter CT, CT, and outputs of the decorder D, D,are respectively applied to the and gates G, (3,. The outputs of the andgates G, G, are sent via the data bus to the computer 1. In theabove-mentioned circuit, the computer 1 can read the contents of thepulse counter selected by the above-mentioned address information. Whendifferent kinds of pulse counters are used in the input-output controlunit 7, the diagnoses are carried out on every group kind by providingthem with diagnose signals which correspond to each pulse counter.

The above-mentioned explanation is given in the case of diagnosing thepulse counters, and it will be understood that the same diagnosis iscarried out for buffur memories, analogue-to-digital converters,digitalto-analogue converters, switching circuits, etc. Of course, thediagnosing signal should correspond with the element to be diagnosed.

What is claimed is:

1. System for diagnosing an input-output control unit in a computercontrol system including a computer, a process and an input-outputcontrol unit having an input-output circuit which is normally coupledbetween said computer and said process and transfers a signal from saidcomputer to said process and vice versa, comprising an inhibit gatebeing provided between said process and said input-output circuit ofsaid input-output control unit, the normal input of said inhibit gatebeing connected to said process and the inhibit input of said inhibitgate being connected to said computer, and an OR gate being inserted inseries with the output of said inhibit element, one input of said ORgate being coupled to said computer, during the diagnosing operation adiagnose mode signal being applied from said computer to the inhibitgate whereby the information flow from said process to said input-outputcontrol unit is interrupted, a diagnose signal being applied from saidcomputer to said input-output circuit via said OR gate, and saidcomputer reading the output signal of said input-output circuit inresponse to said diagnose signal and diagnosing said input-outputcircuit.

2. System for diagnosing an input-output control unit in a computersystem including a computer, a process and an input-output control unithaving a plurality of input-output circuits which are connected betweensaid computer and said process, said unit transferring signals from saidcomputer to said process and from said process to said computer,comprising a plurality of inhibit gates coupled between said process andsaid input-output circuits of said input-output control unit, the normalinputs of said inhibit gates being connected to said process and theinhibit inputs of said inhibit gates being connected to said computer,OR gates respectively being inserted in series with said inhibit gates,one input of said OR gates being controllable by said computer; meansfor applying during the diagnosing operation a diagnose mode signalsimultaneously to said inhibit gates from said computer whereby theinformation flow from said process to said input-output control unit isinterrupted, means for applying a diagnose signal from said computer viasaid OR gates to said input-output circuits, AND gates with decodersbeing respectively coupled to said input-output circuits, means forapplying address information to the computer relative to the respectiveinput-output circuits via said respective decoders, and said computerreading the output signals of said input-output circuits by means ofsaid respective address information and diagnosing said input-outputcircuits.

3. A diagnosing system for a computer control system in which there is acomputer and a process, said diagnosing system comprising; aninput-output control unit normally coupled between said computer andsaid process and which transfers a signal from said computer to saidprocess and vice versa, said input-output unit including first switchingmeans normally coupling said process to said unit, said switching meansalso decoupling said process from said unit in response to a firstsignal applied to said first switching means, said unit also includingsecond switching means coupled to said first switching means and to saidunit, said second switching means normally transferring information fromsaid process via said first switching means to said unit, said secondswitching means also transferring a second signal to said unit fordiagnosing a predetermined portion thereof when said first signal isapplied to said first switching means thereby decoupling the processtherefrom.

4. The diagnosing system according to claim 3 wherein said first signaloriginates in said computer.

5. The diagnosing system according to claim 3 wherein said second signalcomes from said computer.

6. The diagnosing system according to claim 3 5 wherein said firstswitching means comprises an inhibit gate and said second switchingmeans comprises an OR gate in series with the output of said inhibitgate.

sense:

1. System for diagnosing an input-output control unit in a computercontrol system including a computer, a process and an input-outputcontrol unit having an input-output circuit which is normally coupledbetween said computer and said process and transfers a signal from saidcomputer to said process and vice versa, comprising an inhibit gatebeing provided between said process and said input-output circuit ofsaid input-output control unit, the normal input of said inhibit gatebeing connected to said process and the inhibit input of said inhibitgate being connected to said computer, and an OR gate being inserted inseries with the output of said inhibit element, one inPut of said ORgate being coupled to said computer, during the diagnosing operation adiagnose mode signal being applied from said computer to the inhibitgate whereby the information flow from said process to said input-outputcontrol unit is interrupted, a diagnose signal being applied from saidcomputer to said input-output circuit via said OR gate, and saidcomputer reading the output signal of said input-output circuit inresponse to said diagnose signal and diagnosing said input-outputcircuit.
 2. System for diagnosing an input-output control unit in acomputer system including a computer, a process and an input-outputcontrol unit having a plurality of input-output circuits which areconnected between said computer and said process, said unit transferringsignals from said computer to said process and from said process to saidcomputer, comprising a plurality of inhibit gates coupled between saidprocess and said input-output circuits of said input-output controlunit, the normal inputs of said inhibit gates being connected to saidprocess and the inhibit inputs of said inhibit gates being connected tosaid computer, OR gates respectively being inserted in series with saidinhibit gates, one input of said OR gates being controllable by saidcomputer; means for applying during the diagnosing operation a diagnosemode signal simultaneously to said inhibit gates from said computerwhereby the information flow from said process to said input-outputcontrol unit is interrupted, means for applying a diagnose signal fromsaid computer via said OR gates to said input-output circuits, AND gateswith decoders being respectively coupled to said input-output circuits,means for applying address information to the computer relative to therespective input-output circuits via said respective decoders, and saidcomputer reading the output signals of said input-output circuits bymeans of said respective address information and diagnosing saidinput-output circuits.
 3. A diagnosing system for a computer controlsystem in which there is a computer and a process, said diagnosingsystem comprising; an input-output control unit normally coupled betweensaid computer and said process and which transfers a signal from saidcomputer to said process and vice versa, said input-output unitincluding first switching means normally coupling said process to saidunit, said switching means also decoupling said process from said unitin response to a first signal applied to said first switching means,said unit also including second switching means coupled to said firstswitching means and to said unit, said second switching means normallytransferring information from said process via said first switchingmeans to said unit, said second switching means also transferring asecond signal to said unit for diagnosing a predetermined portionthereof when said first signal is applied to said first switching meansthereby decoupling the process therefrom.
 4. The diagnosing systemaccording to claim 3 wherein said first signal originates in saidcomputer.
 5. The diagnosing system according to claim 3 wherein saidsecond signal comes from said computer.
 6. The diagnosing systemaccording to claim 3 wherein said first switching means comprises aninhibit gate and said second switching means comprises an OR gate inseries with the output of said inhibit gate.